10 things you didn’t know about biodiesel

By Unsealed 4X4 10 Min Read
Image from the 'Madigan Line Simpson Desert Crossing' trip for Pat Callinans 4x4 Adventures in June, 2015

Let’s face it, things are only going to get harder as far as the environment goes. Whether you subscribe to the idea it’s all a Greenie push to make money, or that we’re just starting to realise our impact on the environment, there’s no denying green fuel is going to start becoming more and more popular. And hey, if the financial side of things adds up then why the hell not keep the Greenies and the back pocket happy! You’ve all seen the ads for green fuels with people happily strolling through fields of flowers that somehow relate to a turbo diesel 4X4, so we’re taking a closer look at biodiesel. Just what it actually is, what it costs, and what it means for us off-roaders.


You can make it yourself

If you’ve ever fantasised about being the crazy person in your street cooking meth in your garage (and let’s face it, who hasn’t), then you’ll be delighted to know you can make biodiesel at home. The process is simple in theory. You’re starting off with something called Triglycerol. It’s a molecule of Glycerol with three Fatty Acid Strings coming off it, commonly found in animal or vegetable fats. The process involves filtering the old food particles out of the oil, then using a catalyst to break apart the Triglycerol molecule. The heavy glycerol forms a goo in the bottom of your container while the fatty acid strings bond with Methanol – creating Fatty-Acid-Methyl-Ester, the technical name for biodiesel. There are a few other important steps; but that’s the basics.

It’s not that time consuming

Making biodiesel can be a long and drawn-out process, but the actual hands-on side of things can be kept pretty minimal. More involved processing equipment generally involves mixing pumps and storage tanks, meaning you only need to be present for a few key steps in the process over a few days. If you’re buying pre-made biodiesel from a service station, it’s literally just pump and go.


No significant power loss

The big concern with E10 and other biofuels is always a reduction in power. Well, things aren’t much different with biodiesel; although not as bad as you’d imagine. A 5% mix of biodiesel and regular diesel known as B5 results in a 0.5% loss in power. Hardly enough to notice. But if you’re going all-in with 100% biodiesel (B100) it’d result in a 10% loss in power. Not a huge difference in relatively low-power 4X4s, but you’d notice it when you put your foot down.

The cost savings are huge

Kits can cost in the thousands of dollars to distil your own, but you are able to piece them together if you’re handy on the tools. Also expect to use up a corner of your shed. Methanol costs roughly $1.50-ish per litre, so the costs ultimately get soaked up by the equipment and the oil you use. Free oil and DIY equipment? You’ll save a fortune. An expensive kit and paying for oil? You better enjoy making diesel because you’re not saving much money, if any.

It’s kind of better for the environment

Sorry, Mr Prius, but biodiesel derived from waste cooking oil can see reductions in greenhouse gases by as much as 75% over standard diesel. For biodiesel derived from Canola or Tallow it’s still a significant 25% reduction in greenhouse gases. It’s not all sunshine and lollipops though. Certain blends of biodiesel can see NOx levels rise by as much as 16%. So we might protect the Ozone layer; but with a slight increase in the chance of acid rain, yikes! And that’s without getting into the issue of deforestation to plant cheap vegetable oil producing trees. Sorry Orangutans, but you had a good run.

You can make it out of people

Slow down there, Hannibal Lector; while the fats used in biodiesel can be harvested from people, the real upside is that the same fats are found in animals and plants. This means we can literally grow every component required to make the fuel to run our diesel engines. If we’re smart with how we go about it, biodiesel could stave off the electric revolution and keep our diesel 4X4s purring for years to come. Even the by-products of the process can be turned into soap. Diesel soap? Now you’re talking!


We’re literally throwing the stuff down the drain

Currently we treat waste cooking oil like garbage. It gets poured down drains clogging up sewers; bottled and dumped into landfill sites; or it simply gets burnt. With a small investment and a little time this oil can be cheaply and efficiently turned into fuel. It won’t solve the energy crisis, but it’ll definitely help. It’s been worked out that all the grease used for cooking in one major city for one day could power several hundred cross-country flights.

You’ve probably already run it

Just like Ethanol, biodiesel is rated in grade. B100 is full biodiesel, B5 is 5% biodiesel, and so on. If you’ve ever swung through a servo and grabbed some eco-diesel, this is exactly the stuff you’re running. Rather than being cooked up at home it’s mass produced and blended with regular diesel – ready to be pumped into your 4X4 from the local servo.

It isn’t bad for your engine, unless it is

There’s a few issues with running biodiesel in ANY engine. The first is contaminants clogging pumps, filters and injectors; it’s a big ask to filter out every piece of contaminant from previously used oil. The second is lubricity. Diesel fuel is already an oil, so it keeps moving components such as injectors and pumps lubricated; luckily most biodiesel is actually more lubricating than regular diesel. The third issue is a clean fuel system. Over time build-up can occur in any fuel system. Biodiesel will actually clean out your tank and lines, but the resulting goo will all go down the line and it can cause damage … although increasing fuel filtration and monitoring can negate this.

Biodiesel aint biodiesel

There’s more than one way to run an environmentally friendlier engine. The term ‘biodiesel’ sounds like a catch-all for anything green you can run your diesel engine on, but it’s actually not. Biodiesel is fatty oils refined into a chemical compound that looks and acts pretty well exactly the same as regular diesel. You’re converting the fuel to suit the 4X4. Some backyard scientists run 100% waste vegetable oil instead. It’s considerably thicker than biodiesel, requiring on-board heating equipment to thin it out to pass through your engine… changing the vehicle to suit the fuel.

So, should you or shouldn’t you run biodiesel?

After countless hours of research, speaking to the people who either make it, or deal with the after effects of it, we can answer with a strong maybe. B100 (fuel manufactured solely from plant or animals, not petroleum sources) is rare in this country. Blends such as B5 and B20 (biodiesel blended with mineral diesel) are more common, but engines running on it are not warranted by many diesel specialists. Apparently B100 in particular has a solvent affect on your fuel system which can clog filters, so make sure you check your engine can handle it before rushing out and topping her off with veggie oil.

It also has a large barrier for entry with a reasonable understanding of how chemistry works as well as a not-insignificant financial outlay buying the equipment. Can you save money? Yes, in exchange for your time and noodle power. Make no mistake, biodiesel is the way of the future. But the future won’t come one garage chemist at a time. Besides, you’d make more money cooking meth.


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